1. Field of the Invention
Embodiments disclosed herein relate to a driving assistance technique.
2. Description of the Prior Art
As to vehicles as transport means, various research has recently been performed not only for the improvement of gasoline mileage and performance of a vehicle, but also for control devices that are capable of preventing or avoiding a risk caused in driving a vehicle by the carelessness of a driver.
Typically, a Smart Cruise Control (SCC) device, a Highway Driving Assist (HDA) device, and a Traffic Jam Assist device may be exemplified.
Such control devices sense a distance between the own vehicle and a forward vehicle that travels in front of the own vehicle in the same lane, and control an acceleration device or a braking device of the own vehicle so as to maintain a predetermined distance between the own vehicle and the forward vehicle.
That is, the above-mentioned control devices may operate normally or abnormally depending on whether the distance to a forward vehicle is correctly sensed.
In general, a radar and a camera, which are capable of remote sensing, are used as sensing means installed in the own vehicle so as to sense a forward vehicle.
However, the radar has a limitation in that it cannot correctly sense a collision point with respect to a forward vehicle that is obliquely positioned with reference to the own vehicle. Similarly, the camera has a limitation in that it cannot recognize, within a short distance, a forward vehicle that is obliquely positioned with reference to the own vehicle.
The above-mentioned control devices may operate abnormally as the distance to the forward vehicle may not be correctly sensed due to the above-described limitation.
On the contrary, when an ultrasonic sensor is used, there is an advantage in that a forward vehicle, which is obliquely positioned with reference to the own vehicle, can be correctly recognized. However, the ultrasonic sensor has a disadvantage in that its sensing distance is short.